When teenager Gareth Williamson was mugged twice within a short time, he and his family despaired.

Gareth, of Rushden, Northamptonshire, was 17 when he was first attacked by thieves, who made off with his moped. His family believe he was targeted because he has mild learning difficulties.

Just as Gareth was due to give evidence against the suspects being prosecuted for the robbery, he was forced off his moped a second time and chased into a nearby pub.

Gareth was deeply affected by the incident but felt confident that the evidence for the second prosecution would be strong – customers and staff in the pub had helped him and the incident was captured on CCTV.

But, instead, Northamptonshire police responded in a manner they now acknowledge was deeply inadequate. They failed to investigate and, when Gareth and his family made a complaint, still no steps were taken to arrest his attackers.

Gareth was ignored, he says, because of his learning difficulties. "I was not believed because I had learning difficulties and as a result the people who attacked me have still not been brought to justice."

Only after he brought a legal claim under the Human Rights Act and disability discrimination law was his case finally taken seriously.

When agreeing to settle the claim out of court, the chief constable accepted "serious failures" and an "unacceptable" level of service.

"For these mistakes I, and the organisation, are very sorry," he wrote. He also agreed to pay £70,000 in damages and legal costs.

But, says the lawyer who represented Gareth, had the police taken a human rights focused approach to the way they dealt with Gareth in the first instance, expensive and drawn-out legal proceedings would not have been necessary. "It should not have required litigation for the police to honour its duties to people with disabilities in Northamptonshire," says Tony Murphy, of Bhatt Murphy solicitors. "Sadly I am dealing with these kinds of cases nationwide."

Gareth and his family say the case indicates that the police still have a long way to go in recognising that people with learning difficulties and other disabilities have the right to be treated fairly as victims of crime.